Method of making ingot of non-ferrous metals and alloys thereof



lCHlJl OBINATA ETAL METHOD OF, MAKING INGOT OF NON-FERROUS METALS AND ALLOYS THEREOF Filed Feb. 13, 1957 Ill m IIIH INVENTOR.

United States Patent METHGD OF MAKING INGOT 0F NON-FERROUS METALS AND ALLOYS THEREOF Ichiji Obinata,

ikko, Japan, Iron, Steel and Sendai, Japan Application February 13, 1957, Serial No.

3 Claims. (Cl. 22-210) Sendai, and Takejiro Komatsubara, assignors to The Research Institute for Other Metals of the Tohoku University,

mold itself and also for its manufacture,

unhomogeneous crystal structure inner defects such as blow holes and has disadvantages of making the after-working and heat-treatment difficult and also reducing the yield.

In a known continuous casting process using a water and accompanies many is caused to successively deposit or accumulate on the previously poured and solidifying mass in the mold to form a cast mass making turbulent and violent interphase C. becomes slow so that the molten state may be maintained for comparatively long duration and the occluded gases can be ejected very easily, thereby resulting a sound ingot. In this case, the total volume of hot liquid in the bath is sufiicient with about 300 times the inner volume of the mold.

In a modified of statical casting embodiment of this invention, instead process using a completely fixed metal mold, the bottom of mold fixed in a hot liquid bath such as hot water bath is mounted on a movable support to be distance when the molten pieces of needle form and never forms a sound ingot. On the other hand, if the is raised above about 30 C.

can be obtained.

in case of making an ingot of copper and its alloy, the temperature of hot liquid such as hot water or hot oil may be selected as desired below the boiling temperature of water and to room temperature, but the lower temperature affects somewhat the surface of solidified mass according to the kind of copper alloys. But dilferent and copper alloys soundness of the ingot.

For a better understanding of this invention reference embodiments thereof, taken companying drawings, wherein,

Fig. 1 is a sectional elevation of a casting device for carrying out this invention;

Fig. 2 is a sectional elevation of a device for carrying out continuous casting in accordance with this invention;

T 3 is a sectional view of a 99.5% aluminum ingot according to this invention showing the macro-structure etched in aqua regia;

Fig. 4 is a similar sectional view to Fig. 3 of a 99.5% aluminum ingot made by conventional casting method using an ordinary ironimold.

Now referring to Fig. 1, 1 represents a water tank filled with hot water 2 at C. amounting to about liters. having 4 is a graphite crucible having a small hole 5 diameter) at its bottom.

In carrying out the method of this invention, a molten metal a In Fig. 2, the same or similar parts are represented by the same reference numerals as in Fig. 1. In this case, the bottom 8 of mold 3 is made separately and supported on a movable support 9 and the molten metal such as 99.7% aluminum previously fused in and fed into the crucible 4 is flown down through its bottom hole 5 at a temperature of about 680 C. into the mold 3 similarly to the manner as explained with respect to Fig. 1. As the molten metal in the mold has solidified to a desired extent the movable support is slowly lowered carrying the solidified aluminum ingot on it, and again cast the molten aluminum, thus repeating this process an ingot having a diameter of 60 mm. and 700 mm. long was obtained. The temperature of water used was 90 C.

In the example of making an ingot of copper and its alloy according to this invention, the temperature of water was taken for example at about 84 C. and a mold made of copper plate 2 mm. thick having inner diameter of 50 mm. and 230 mm. high was immersed into hot water in the tank, and the molten Phosphor bronze at a temperature of 1130 C. was cast through the hot water into the mold and solidified in the hot water.

In using the device as shown in Fig. 2, the movable bottom support 9 was lowered gradually as the molten Phosphor bronze is poured into the mold 3 and a Phosphor bronze ingot 10 of 540 mm. long was obtained.

The aluminum ingot made by the method of this invention showed uniform and fine granular structure as shown in Fig. 3 and the test piece of this ingot showed the attenuation of 0.33 db/cm. at the frequency of 3 mc./sec. as the result of test by an ultrasonic reflectoscope. On the contrary, the ingot made by an ordinary metal mold casting process showed the structure as shown in Fig. 4 and the attenuation of 0.56 db/ cm. at the same condition, the latter being about twice as high as the former. Moreover the ingot according to the method of this invention has improved mechanical properties superior to those of ordinary method. For instance, comparative tests of aluminum ingots of 99.9% and 99.5% purity made by the method of this invention (A) and ordinary metal mold casting process (B) are shown in the following table:

a melting furnace In case of copper and copper alloys, the ingot made by the method of this invention showed more homogeneous, fine macro-structure than that obtainable by heretofore ordinary method and the test results of inverse segregation of tin in case of Phosphor bronze are shown as follows:

Position (refer to Fig. 3) Segregation of tin, percent (A) Superficial layer 8.77 (B) Outer layer 8.65 (C) Inner part 8.68 (D) Central part 9.00

Thus very good ingot of Phosphor bronze can be made by the method of continuous casting according to this invention without substantially inverse segregation which gave troubles to working and heat treatment in the ingot made by an ordinary process.

What we claim is:

1. A method of making ingots of non-ferrous metals such as aluminum, zinc, copper and alloys thereof, which comprises pouring a molten metal directly into a liquid contained in an open bottom mold which is completely immersed in said liquid and causing the molten metal to deposit successively on the previously poured and solidifying mass after making turbulent and violent interphase agitation between molecules in the mass, thereby resulting in a uniform and homogeneous dispersion and mixing of particles and ingredients, and completing the solidification of the metal mass in said liquid.

2. A method of making a comparatively long ingot of non-ferrous metal such as aluminum, zinc, copper and alloys thereof according to claim 1, the mold having a movable bottom, comprising gradually lowering the movable bottom of the mold when the cast molten metal has solidified in the mold to a desired extent thereby producing an ingot of a desired length in continuous manner.

3. A method of making ingots of non-ferrous metals according to claim 1 which comprises using a liquid bath of water at a temperature of to 90 C.

Elongation Purity of Oasting Temp. of Average Tensile percent Mold Aluminum temp, water, specific strength mark 0. C. gravity kg./mm. distance,

' mm thick 1 99.9 680 2.728 4.56 to 5.35 44-56 Math f i2 99. 5 680 2.745 6. 39 to 7.88 223-41 1mm thick.

(1 99.9 680 -90 2.729 6.13 to 6.86 52-60 Math References Cited in the file of this patent UNITED STATES PATENTS 262,625 Small Aug. 15, 1882 2,298,348 Coxe Oct. 13, 1942 2,304,258 Junghans Dec. 8, 1942 2,363,695 Ruppik Nov. 28, 1944 

1. A METHOD OF MAKING INGOTS OF NON-FERROUS METALS SUCH AS ALUMINUM, ZINC, COPPER AND ALLOYS THEREOF, WHICH COMPRISES POURING A MOLTEN METAL DIRECTLY INTO A LIQUID CONTAINED IN AN OPEN BOTTOM MOLD WHICH IS COMPLETELY IMMERSED IN SAID LIQUID AND CAUSING THE MOLTEN METAL TO DEPOSIT SUCCESSIVELY ON THE PREVIOUSLY POURED AND SOLIDIFYING MASS AFTER MAKIING TURBULENT AND VIOLENT INTERPHASE AGITATION BETWEEN MOLECULES IN THE MASS, THEREBY RESULTING IN A UNIFORM AND HOMOGENEOUS DISPERSION AND MIXING OF PARTICLES AND INGREDIENTS, AND COMPLETING THE SOLIDIFICATION OF THE METAL MASS IN SAID LIQUID. 